Fragile X Syndrome - Symptoms, Causes and Treatment

Fragile X Syndrome (also known as Martin-Bell syndrome) is a genetic disorder associated with the expansion of CGG (a single tri-nucleotide gene sequence) on the X chromosome. This syndrome results in failure of effective participation of FMR-1 gene/protein required for normal and neutral development of the offspring and causes changes in the emotional, physical, intellectual and behavioral features.

In other words, Fragile X syndrome causes impairment in various mental activities, behavior, physical and emotional aspects etc. For example: mental impairment, physical disproportion of body features, autism, problem with speech delivery etc.

What are the Causes of Fragile X Syndrome

Fragile X syndrome is a genetic disorder caused due to problem with FMR-1 gene (such as mutation) which is situated on X chromosome. The probability of an offspring carrying this disorder is 1 in about 4000. The CGG codons in Fragile X syndrome are more than 230 repetitions (as against 6 to 55 repetitions in a normal case). Absence of production of FMRP (fragile X mental retardation protein) leads to onset of Fragile X syndrome. As mentioned above, inheritance is also one of the causes of Fragile X syndrome. Changes in brain anatomy also have been identified as one of causes of Fragile X syndrome.

Problems Associated with Fragile X Syndrome

• Fragile X syndrome in some children (study shows that about 3 to 6 percent children develop autism at varying degree because of Fragile X syndrome) may trigger autism or Autism Spectrum disorder (ASD).
• There exists a possibility of developing tremor or ataxia syndrome that affects balance, tremor and memory like issues with some gene carriers.
• Some females who are carrying Fragile X syndrome may experience problems associated with ovarian function leading to conditions such as issues with menopause or infertility etc.
• Children born with Fragile X syndrome are prone to problems such as mental retardation, physical abnormality, problems with behavior etc.

Symptoms of Fragile X Syndrome

• As mentioned above, those who are suffering from Fragile X syndrome may develop mental retardation or mental control related problems.
• Their physical, behavioral and mental characteristics are different from that of normal people such as large/protruding ears and testicles, elongated face, flat feet, abnormal behavior such as flapping of hands and hand biting etc.
• Problem with speech (cluttered, nervous or unclear etc.)
• Problem with concentration
• Low muscle tone
• Problems with menopause or infertility in females.
• Development of autism in some cases etc.

How is Fragile X Syndrome Diagnosed

The initial diagnosis is based on the symptoms associated with this disorder such as patient’s speech test, behavioral, intellectual and physical characteristics observation. As mentioned above, this disorder is also genetic; hence knowing patient’s family history can also help in diagnosing the disease. Along with the above observations and study based diagnosis, this syndrome is also determined with the help of analysis of number of CGG repetitions and their methylation status (methylation status is found with the help of restriction endonuclease digestion and Southern Blot Analysis).

Treatment for Fragile X Syndrome

Currently, there is no cure available for this disorder. However, there is a lot of research going on and efforts are being made to understand the underlying causes, which has made it easy to recognize and develop new methods and therapies to treat the disease. The only help available for patients suffering from this disorder is in the form of symptom based treatment which includes behavioral, physical, emotional and intellectual characteristics. Medication is used to control mental, physical and emotional aspects, and other options such as specially devised education, behavioral therapy etc. are also used.